I'm not sure which revision of Powerbook you're referencing but since the 12" wasn't revised when the 15" and 17" were just recently (pretty sure that's correct), I would venture, per this page @ http://www.apple.com/powerbook/index12.html that the 12" DOES have the "80GB or 100GB 5400-rpm Ultra ATA/100 hard drive with Sudden Motion Sensor".